The control of printing machines and the monitoring of the printing processes running thereon are increasingly being undertaken from central control consoles. These central control consoles are composed of a number of operating elements and at least one planar display device on which information can be represented. As a rule, the operating elements are an alphanumeric keyboard with cursor control keys for the direct entry of data or numerical values. Of particular importance to this invention is the use of control menus in which printing machine settings can be monitored and adjusted, and other information about the printing process can be recalled upon command. Performing these tasks has been inefficient and accomplished through repetitive operator action. Conventionally, menu-driven user interfaces have a specific number of menu items always represented on the display device. Using cursor control keys to highlight one or more of menu items, an operator initiates a command via the actuation of a special input key. Additional selections under a menu item and other menus can be called up and selected in an analogous way.
Other implementations of menu interfaces for printing machine control systems frequently use function keys to select and initiate commands. The use of a high number of function keys causes lack of clarity and harbors the risk of operator error. Similarly, recalling information or selecting and initiating commands via cursor control keys is prone to operator errors.
Control devices for printing machines sometimes have a rotating control device that operates in two dimensions, for example, in German Patent No. DE 3 614 406 C2. In this patent, a control device of a rotary offset machine includes a digitizer in the form of a control ball operable in two dimensions. Rotating this control ball in the X-axis calls up for adjustment the actuators of the ink film thickness profile, the actuators of the damping solution thickness profile, or another register. Subsequent actuation of the control ball in the Y-direction then causes incremental adjustment of the called actuator or register. One main disadvantage of such a control ball or equivalent results from the activation of different sets of commands based on the direction of movement of the control ball. This allows commands to-be inadvertently activated by erroneous movement of the control ball in one direction when attempting to move the control ball only in a single, different direction. In practice, an operator must limit movements of the control ball to a single direction. The operator therefore carries out operating actions with a heightened level of attentiveness which leads to unnecessary strain and is unnecessarily inefficient.
The disadvantages named above also arise in the use of a two-dimensionally operated control device to select menu items from a display console. For example, in Zingher et al. U.S. Pat. No. 5,091,859, issued Feb. 25, 1992, a printing plant control system uses a rollerball to control commands. This patent describes a control system with menu guidance provided to the operator by means of command cycles which can be called up. A rollerball, which can be moved in two dimensions, is assigned a data release key which is used to initiate a command that is called up and highlighted on the display device. The use of the rollerball in the printing control system operator interface has many disadvantages including its two dimensional operation of the rollerball, being difficult to use, and its tendency to promote errors by the printing machine operators who are typically wearing gloves.
Machine control units composed of a personal computer with a mouse that can be moved through a horizontal plane are also known. The disadvantages of the two dimensional operation and difficulty of use by printing machine operators as described above also are inherent in the use of a mouse control device. Furthermore, the operating consoles of printing machines generally have inclined working surfaces for the purpose of assessing the print copies. A mouse control device is difficult to use on an inclined work surface, and is prone to cause errors as gravity causes the mouse to move on its own. Thus, it is necessary to find a parking surface on the inclined working surface for on which the mouse can be placed.
The control devices described above do not provide the printing machine operator an effective means to control the operation of a printing machine. These prior devices require inefficient, time-consuming, and extraneous efforts for error-free control of the printing machine.